There are several options for free software to convert an image to black and white. XnConvert is one option that is easy to use and runs on Windows, Mac, and Linux. There is also a portable version available for both 32-bit and 64-bit versions of Windows and Linux. Another option is Canva, which allows you to apply a black and white filter to your pictures with just one click. Fotor is another online tool that makes it easy to convert images to black and white, and it offers a variety of filters and effects to customize your image. Additionally, Adobe Express offers a free online black and white filter that you can use to transform your photos. Adobe Photoshop Express is another option that allows you to explore different black and white photo filters and vintage aesthetics.